Tilting pad journal bearings



Feb. 20, 1962 J. M. GRUBER 3,022,123

TILTING PAD JOURNAL BEARINGS Filed Sept. 2l, 1959 2 Sheets-Sheet 1 B EITOR. j.

Feb. 20, 1962 J. M. GRUBER 3,022,123

TILTING PAD JOURNAL BEARINGS Filed Sept. 2l, 1959 2 Sheets-Sheet 2 A TTORNEMS'.

United States PatentjO" 3,022,123 TILTING PAD JOURNAL BEARINGS Jerome M. Gruber, Waukesha, Wis., assignor to Waukesha Bearings Corporation, Waukesha, Wis., a corporation of Wisconsin Filed Sept. 21, 1959, Ser. No. 841,121 7 Claims. (Cl. 30S- 73) This invention relates vto improvements :in tilting pad journal bearings.

Tilting pad journal bearings are in common use for a number of purposes. In certain applications, however, where there are strains on the shaft producing a certain amount of deflection, the pads of the conventional tilting pad journal bearing are not capable of maintaining a desired alignment. This is particularly true of bearings for use in gyroscope applications on board a submarine where the shaft is generally vertical `but is adapted to tilt back 'and forth.

It is a general object of the present invention to provide an improved tilting pad journal bearing, wherein the pads are so supported that they are capable of automatically aligning themselves axially las well as circumferentiallyt A more specific object of the invention is to provide a tilting pad journal bearing wherein each pad is supported on a rocker plate, each rocker plate being transversely convex for conventional rocking movement of the pad and also longitudinally convex to provide for rocking of the pad in a direction at right angles to the first direction.

A further object of the invention is to provide a tilting pad journal bearing having improved means for supplying oil to each pad directly and having improved means for the discharge of said oil whereby the pads operate submerged to increase damping.

A further object of the inven-tion is to provide a tilting pad journal bearing wherein there are readily detachable end covers having trunnion holes for cooperation with trunnions on the pad rocker plates, said trunnion holes serving to support the plates and pads and to accurately locate the pads in axial alignment with the shaft, the t of the trunnions in said holes being loose to permit limited rocking of the pads on the longitudinal convexities of the outer faces of the rocker plates.

A still further object of the invention is to provide an improved tilting pad journal bearing as above described wherein the rocker plates `are detachably connected to the pads in a way to permit shirmning between the plates and pads whereby the clearance at the bore may `be varied.

A further object of the invention is to provide an improved tilting pad journal bearing which is relatively simple in construction, which can be quickly disassembled for repair, which is strong and durable, and which is otherwise well adapted for the purposes described.

With the above and other objects in view, the invention consists of the improved tilting pad journal bea-rin g, and all of its parts and combinations, as set forth in the claims, and all equivalents thereof.

In the accompanying drawings, in which the same reference numerals designate the same parts in `all of the views:

FIG. l is a perspective view of the bearing showing it in generally upright position;

FIG. 2 is a cross-sectional View taken on the line 2 2 of FIG. 3, the dot and dash lines indicating how it is adapted to t in a machine frame;

FIG. 3 is a top view of the bearing, parts being broken away and shown in section; and

FIG. 4 is a perspective view of one of the tilting pads with its attached rocker plate, looking at the outer convex faces.

Referring more particularly to the drawing, numeral 3,022,123 Patented Feb. 20, 1962 ICC designates a housing which, in the embodiment shown, has ya spherical outer periphery 11 provided with a peripheral oil groove 12. The housing illustrated is adapted to coact with a suitably shaped frame part, the'shape of which is shown diagrammatically bypdot and das-h lines -at 13 in FIG. 2. 'Ihis provides a self -aligning spherical seat for the housing, and there is, of course, suitable means -for supplying oil under pressure to the groove 12.

Detachably secured by bolts 14 to lthe ends of the housing 10 are ring-shaped covers or end plates 15 and 16. On the inner faces of the covers surrounding the central opening are annular recesses 17 and 18 respectively. In addition, there are oil collecting grooves 19 and 20 respectively. The cover member 15, which is adapted to be the top cover when the bearing is disposed in the upright position of FIG. 1, is formed with radially extending oil holes 21, the inner ends of which connect with the oil collecting groove 19 and the outer ends of which extend through the outer periphery of the end covervto the exterior. On a tive-pad bearing there are preferably tive oil holes but this exact number may be varied. These oil holes 21 in the top cover allow oil to ow out from the top of the bearing when the bearing is in the upright position of FIG. l, las will be hereinafterexplained. If desired for other applications, the oil holes may be used in both covers but in the illustrated embodiment of the invention they are shown only in the top cover to obtain submerged operation.

The cover plates 15 and 16 project inwardly a substantial distance beyond the bore 22 of the housing 10 to form therewith 4an annular pad-accommodating groove 23 for receiving tilting pads 24. Each pad has a concave inner face to fit `the shaft which is to be journalled in the bearing, and said faces are preferably lined with |babbitt, as at 25. In the embodiment of the invention shown there are ive pads which are adapted to embrace the shaft which is to be journalled in the bearing. The number of pads, however, may be varied as required.

The outer face of each pad is convex to substantially match the bore 22 of the housing and each outer face is provided with an axially extending groove 27 for detachably receiving an axially extending rocker plate 28. The rocker plates are adapted -to be held in position by screws 29 and there may be shims in the joint between the inner face of each rocker plate and the bottom of the groove 27. These shims may be .001" and .0015, and by varying the number of shims the clearance may be varied as desired. With the detachable rocker plate construction this change of shims may be easily accomplished. The outer face of each rocker plate 28 is transversely convex or crowned as shown in FIG. 3, so that the connected pad can adjust circumferentially around the shaft. In addition, however, it is a novel feature of the present inventhat each rocker plate is convex or crowned in a longitudinal or axial direction to a much lesser degree than the transverse crowning, as indicated at 30 in FIG. 2 in an exaggerated manner for purposes of clarity. This allows the rocker plate and its connected pad to axially align itself with the shaft to adapt itself to conditions encountered in use.

In order to permit this rocking of the plates on the longitudinal convexities 30, end trunnions 31 of the plates t loosely in holes 32 in the end covers 15 and 16. These holes in one of the covers such as the top cover 15 preferably extend through as illustrated in FIG. 1. It is to be noted that each rocker plate 28 is preferably connected to its pad so -as to be offset somewhat toward one side of the pad, as is clear from FIG. 3. The actual clearance at a is only .005 in the illustrated embodiment, but thismay vary to meet requirements. In any event the crowning at 30 is very small so that the rocker plate has a relatively long contact area so as to maintain a highv load carrying capacity. Y Y

Y The use of the solid housing arrangement with readily separable end covers having accurately positioned holes 32 for' receiving'the trunnionsV 31 of the rocker plates provides for accurate location of the Y'pads in axial alinernent with the shaft whenever the end cover plates Yare connected by their bolts 14 and dowels 14.

In order to provide a measure of the temperature of the babbitt on the pads it is preferred to have temperature responsive devices 33 inserted in each pad in contactrwith the babbitt, there being flexible electric leads 34 extending through holes 35 in the pads and leading out through openings 36 in the ghousing'to a suitable instrument.

In use of the journal bearing, with a shaft embraced by the pads 28, itis apparent that'dueV tothe novel contour on the outer faces of the rocker lplates 2,8 that the pads are capable of axial as well yas circumferential alinement with the shaft. VLimited rockin-g of the rocker plates on the longitudinal convexities is permitted by'the loose iit of the trunnions 31 in the cover plate holes 32. During use, the housing Vgroove 12 is kept filled Ywith oil Vunder pressure and this oil flows into the oil cups'3'7 in the housing 10 and out of the oil inlet lholes 38 which lead yfrom the cups'to thepad accommodating groove 23. There is preferably one oil inlet hole 38 for each pad. With this Y arrangement the bearing is kept constantly lled with oil,`

which oil continuously ows out of the outlet holes 21 in the-cover 15. In -this way the pads operate in a submerged condition, increasing the damping action. Due ,Y to the fact that the pads can rock in two directions at right angles to one another, the pads are capable of adapting thernselves to deflected conditions of a shaft which is journalled in the bearing when the shaft is under arstress which proA duces such deflection.

It is'to be understood that the present invention is not to be limited to the exact details of construction shown and described for obvious modifications will occur to persons lskilled in the art.

What l claim is: Y

1. In a tilting pad journal bearing having an'annular housing with aV peripheral wall -and with a bore and having an annular series of arcuate tilting pads'within said housing positioned -to embrace a shaft therebetween,

readily detachable ring-shaped covers on the ends of said housing forming with the housing an annular pad-accommodating groove, the peripheral wall of said housing having oil holes at circumferentially spaced points adapted to conduct oil from an outside source to said pad-ao commodating groove, one of said ring-shaped covers having a grooved inner periphery and having radialiy extending oil holes extending outwardly from said grooved inner periphery and providing vfor the discharge of oil Yin a radially outward direction from Athe shaft.Y

2. ln a tilting Vpad journal bearing having an annular housing with a bore and having aniannular series of i arcuate padswithin said housing positioned to embrace a shaft therebetween, an axially extending rocker plate detachabl-y bolted to and projecting from the outer side of each pad, there being ashim accommodating joint between Vsaid plate and pad, each rocker plate having a transversely convex outer face for rocking engagement with Vthe V,bore of the housing, and end retaining means on said housing positioned to lsupport said plates and pads. 4 3. In a tilting pad journal bearing having an annular housing with a bore and having an annular series of arcuate pads within said housing lpositioned to embrace a shaft therebetween, an axially extending rocker plate detachably connected to and projecting from t-he outer side of eac-h pad, each rocker plate having a transversely convex outer face for rocking engagement Vwith thebore of the housing and having end trunnions, Va'pair of ringshaped end covers for said housingafiidpads, said end covers having trunnion Vholes positioned to rockably receive said plate trunnions to support saidY plates and pads and to accurately locate the pads in axial .alignment with the shaft. Y

4. In a tilting pad journal bearing having an annular housing with a bore and having an annular series of arcuate pads within said housing positioned to embrace Va shaft therebetween, an axially extending. rocker Vplate detachably connected to and projecting fromthe outer side of each pad, each rocker plate having a transversely convex outer face free of connection with said bore for rocking -movement in the bore ofthe housing and having end trunnions, a pair of ring-Shaped end retaining members forY said housing and pads, at least one of which is removable, said end members having trunnion holesrpositioned to rockably receive said plate trunnions to support said plates and pads and to accurately llocate the pads in axial alignment'with the shaft,V said transversely convex outer face normally having only centraicontact with said housing bore so that there may be rocking on the trunnions Without necessity of slidingmovement whereby said rocking may take place under high loads without freezing.

- 5. In a tilting pad journal bearing having an annular housing with a bore and having an annular series of arcu- Xate pads within said housing positioned to embrace a shaft therebetween, an axially' extending rocker plate detachably connected to and projecting from the outer side of each pad, each rocker plate having a transversely and longitudinally convex outer face lfree of connection with said bore forfrocking movement in two directions at right angles to one another inthe bore of the housing and having end'trunnions, a pair of ring shaped end retaining members for said housing Yand pads, said end members having trunnion holes positioned to rockably receive said plate trunnions to support saidrplates and pads and to accurately locate the ypads in axial alignment with the shaft, the fit of the trunnions in the holes being loose to permit only limited rocking of the pads on the longitudinal convexities of the outer faces of the rocker plates, said transverse and longitudinally convex outer face portions normally having only central contact with said housing bore so that there may be rocking in either direction without necessity of sliding movement whereby said rocking may take place underrhigh loads without freezing. A d

l 6.V In a tiltingV pad journal bearing havingY an annular housing with a bore and having Van annular series of arcuate pads within said housing positioned to embrace a shaft therebetween, an anxially extending rocker plate projecting from the outer side of each pad, each rocker plate having a transversely and longitudinally convex outer face free of connection withy said bore for rocking movement in two directions at right angles to oneY another in the bore of the housingV aud having end trunnions, a pair of ring shaped end retaining members for said housing and pads, said end members having trunnion holes positioned to rockably receive said Vplate trunnions to support said rplates and pads and to accurately locate the pads in axial alignment with the shaft, the fit of the trunnions in the holes being loose to permit only limited rocking of the pads on the longitudinal convexities of the outer faces of the rocker plates, said transverse and longitudinally convex outer face portions normally having only central contact with said housing bore so that there may Vbe rocking in either direction withoutrnecess'ity of sliding movement whereby said rocking may take place under high loads Without freezing. Y

7. In a tilting pad journal bearing Vhaving an annular housing With a bore and having an annular series of arcuate pads within said housing positioned to embrace a shaft therebetween, an axially exending elongated rocker plate connected to and Yprojecting from the outer side of each pad, each rocker pltae having a transverse convexity on its outer face and having a substantially lesser longitudinal convexity on its outer face free of connection wth said bore for rocking engagement in two directions at right angles to one another in the bore of the housing and having end trunnions, a pair of ring shaped end members for said housing and pads, said end members having trunm'on holes positioned to rockably receive said plate trunnions to support said plates and pads and to acurately locate the pads in axial alignment with the shaft, the iit of the trunnions in the holes being loose to permit limited rocking of the pads on the longitudinal convexities of the outer faces of the rocker plates, said transverse and longitudinally convex outer face portions normally having only central contact with said housing bore so that there may be rocking in either direction toward one of the trunnions as permitted by the loose iit of the trunnions in their holes whereby said rocking may taken place under high loads without freezing.

References Cited in the iile of this patent UNITED STATES PATENTS Parsons Nov. 23, Hudson Jan. 12, Haas Mar. 2, Sherbondy Feb. 21, Balsiger Apr. 24,

FOREIGN PATENTS Great Britain May 10, Great Britain Aug. 21, Germany Oct. 3, 

